The U.S. Army Corps of Engineers will hold an online information session about its summer forecast for its Willamette River system of dams and reservoirs.

As of May 23, the overall level for the 13 reservoirs is 86% full.

The event is scheduled for 6-7:30 p.m. May 30, and residents can watch via https://usace1.webex.com/join/WaterManagementNWP.

People can also join by phone at 844-800-2712. The access code for the meeting is 199 939 8180.

USACE encourages questions but asks participants to type questions in a chat window or send an email to cenwp-pa@usace.army.mil with their question by May 29.

Beginning in mid-May, USACE maintains reservoir levels as high as possible to conserve water for recreation and other congressionally authorized purposes.

After the rainfall dwindles in late spring, snowmelt is the primary water source that helps maintain reservoir levels through the summer.

“Balancing flood risk management and reservoir refill for the conservation season in the Willamette Valley is challenging,” said Salina Hart, Portland district chief of the reservoir regulation and water quality section.

“Spring rains are essential for refilling reservoirs but are also a taxing time for flood risk management. Fortunately, our water managers successfully managed May storms, providing flood risk management for downstream communities and improving refill conditions in the system of reservoirs,” Hart said in a news release.”

The primary purpose of the system is flood risk management.

Water managers must keep reservoir elevations low to maintain storage space, capture rainfall and minimize flooding potential through spring.

This must be balanced with what seem to be conflicting purposes: refilling the reservoirs before summer for irrigation, hydropower generation, water quality improvement and recreation.

Water managers continue to operate under 2021 court-ordered injunction measures aimed at improving conditions for endangered fish species. The injunction measures include delayed refills at Cougar and Fall Creek and early fall drawdowns at Green Peter and Lookout Point.

Local officials said the reservoir drawdowns left a “path of destruction,” that included dead fish choking the Santiam River, murky water that stressed municipal systems, tainted drinking water and lost tourism dollars.

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